This invention is described in preferred embodiments in the following description. The invention will be described as removing certain urethane products, such as those sold by DOW Chemical, USA, and/or urethane products formed using certain isocyanates sold by DOW Chemical USA. The following description of the composition in accordance with the present invention, and method using that composition to remove urethane products from a substrate is not meant, however, to limit the invention to the removal of urethane products sold by DOW Chemical USA, or to the removal of urethane products formed using isocyanates sold by DOW Chemical USA.
Embodiments of the present invention comprise a composition, and a method using that composition, to remove urethane products from a substrate. Such products include, without limitation, foams, coatings, adhesives, and the like. Additionally, such urethane products may include other functionalities/repeat units, such as without limitation, ureas, amides, imides, isocyanurates, and the like.
Such products may further comprise full density materials as well as foams. Such full-density products may comprise one or more linear polymers, one or more cross-linked polymers, and combinations thereof.
As those skilled in the art will appreciate, a foam material comprises struts and voids. In certain embodiments, such foam products comprise integral-skin foams comprising a first portion having a first density, wherein that first portion is partially or substantially completely covered by a second portion having a second density, wherein the second density is greater than the first density. Such foam products may comprise one or more linear polymers, one or more cross-linked polymers, and combinations thereof. Such foam products may comprise flexible foams, rigid foams, and combinations thereof. Such foams may further comprise open cell foams, closed cell foams, and combinations thereof.
In certain applications, the urethane product may be formed using a di-isocyanate, such as and without limitation, Toluene Diisocyante (“TDI”), Diphenylmethane Diisocyanate (“MDI”), Hexamethylene Diisocyanate (“HDI”), and the like. In certain embodiments, the urethane product may be formed using a derivative of a di-isocyanate, such as without limitation, a polycarbodiimide-modified diphenylmethane diisocyanate, such as for example and without limitation, Isonate 143L sold by Dow Chemical. In certain embodiments, the urethane product may be formed using a urethane prepolymer having isocyanate end groups, for example and without limitation ISONATE 181 sold by Dow Chemical. In certain embodiments, the urethane product may be formed using polymeric MDI material sometimes referred to as a Polymethylene Polyphenyl Isocyanate or PAPI.
The substrate may comprise a rigid material, such as without limitation wood, metal, glass, engineering plastic, and the like, a flexible material, such as without limitation, a fabric, cloth, a textile, and combinations thereof, and the like.
As those skilled in the art will appreciate, a wide variety of urethane materials are sold in commerce by a number of vendors. As those skilled in the art will further appreciate, many adhesive formulations comprise urethane materials. This being the case, after a urethane material may be disposed on a substrate, that urethane material may be difficult to remove from the substrate. This is particularly true where a urethane foam product may be formed substantially synchronously with the application of one or more liquid components comprising one or more isocyanates, as described herein, to that surface.
For example, for about 10 years Dow Chemical Company has sold, and currently sells, in commerce a urethane gap filler under the tradename GREAT STUFF. That urethane material may be used during residential, commercial, and industrial construction, as well as in post-construction projects by individual home owners. In response to the question “How do I get foam off the side of my house?,” DOW's website provides:                There is no solvent that will remove cured polyurethane foam. Remove as much as possible with a dull scraper or a hacksaw blade and then try scrubbing the remaining film with a non-abrasive cleaner. If that does not work, gradually move up to more aggressive means including sanding, sandblasting and repainting.See, http://www.dow.com/greatstuff/pro/faq.htm#faq1.        
A composition and method using that composition have been discovered to remove GREAT STUFF, as well as a wide variety of other urethane materials, from a wide variety of substrates without resorting to scraping, scrubbing, sanding, sandblasting, and the like.